Lecture 6. Conditions requiring first aid. Stopping breathing and blood circulation, measures to revive the body
Lecture plan:
6.1. Definition of the concept of "first aid". General principles of providing first aid to victims in emergency situations.
6.2 List of conditions requiring first aid. The concept of clinical death. Respiratory and circulatory arrest.
6.3. Determination of signs of human life in the absence
consciousness. Sequence of events
to revive the body
6.1. Definition of the concept of "first aid". General principles of providing first aid to victims in emergency situations.
First aid is a set of simple measures carried out directly at the site of injury as self- and mutual aid, as well as by participants in emergency rescue operations.
First aid measures are aimed at preserving the lives of victims of injuries, poisoning and sudden illnesses.
The goal of first aid is to prevent the development of severe complications. The basis of first aid measures is made up of 3 principles:
First aid measures include:
1. Immediate cessation of exposure to damaging factors (temperature factor, electric current, compression by weights, etc.).
2. Providing first aid depending on the type and nature of the injury (stopping bleeding, measures to revive the body, etc.).
3. Organization of transportation of the victim to a medical facility in accordance with the type and nature of the injury.
First aid is effective only if it is provided as soon as possible after the injury. The optimal time for providing this aid after receiving an injury is from 5 minutes (if breathing has stopped) to 1 hour.
In case of serious damage, the maximum compensatory functions of the body maintain a stable state for 1 hour. Later, as a result of gradual depletion of strength reserves, the body strives to provide the brain with the remains of vital forces.
According to the World Health Organization, 30% of victims with life-threatening injuries die within an hour of an accident without first aid at the scene.
6.2. List of conditions requiring first aid. The concept of clinical death. Respiratory and circulatory arrest
Terminal conditions are pathological changes in the human body, characterized by the progressive destruction of all tissues.
These conditions are characterized by profound disturbances of gas exchange. Since different tissues react differently to the cessation of oxygen delivery to them, their death does not occur simultaneously. The highest section of the central nervous system, the cerebral cortex, is most sensitive to hypoxia. In terminal conditions, the functions of this section of the CNS are switched off first. After the cortex is switched off, changes are also observed in the subcortical sections of the brain. The medulla oblongata, which performs the functions of respiration and blood circulation, is the last to die.
The causes of the development of terminal conditions include: traumatic shock, acute blood loss, electrical injury, burns, drowning, myocardial infarction, etc.
Terminal states represent the process of dying of the organism, the transition from life to death. Dying of the human organism includes 3 stages.
Pre-agony is a terminal condition characterized by the development of inhibition in the higher parts of the central nervous system.
Consciousness is preserved, but its confusion and obscurity are noted. Eye reflexes are preserved, despite the decrease in reflex activity. At the beginning of pre-agony, a short-term excitement may occur, explained by the body's attempt to fight for its life.
Blood pressure is low (up to 60 mm Hg) or not detectable. Heart rate changes are noted - from increase (tachycardia) to decrease (bradycardia). Pulse in peripheral arteries is very weak or absent (pulse is detectable in carotid and femoral arteries).
Breathing is initially rapid and deep, then shallow and rare. Respiratory disorders are manifested by pallor and cyanosis (blueness) of the skin.
In addition, there is a sharp decrease in body temperature and the absence of urine excretion by the body (oliguria). Duration The pre-agonal state is determined by the body's capabilities and ranges from several minutes to a day.
The pre-agony ends with a terminal pause. Breathing stops, the pulse is rare, sometimes absent. Bradycardia is observed, sometimes asystole (cessation of cardiac activity). Loss of consciousness is observed 4-5 seconds after cardiac arrest. Pupil reactions to light disappear, pupils dilate. Respiratory and cardiac arrest are short-term.
The duration of the terminal pause is from a few seconds to 5 minutes. At the end of the above-mentioned state, agony sets in. Since the terminal pause occurs rarely, it is not included in the classification of the stages of the organism's death.
Agony is a stage of dying characterized by profound dysfunction of the higher parts of the central nervous system, especially the cerebral cortex. At this stage, the body's compensatory mechanisms are activated, aimed at combating the fading of vital forces.
In the state of agony, there is a short-term recovery, and then loss of consciousness. The pupils do not react to light, the pupils are dilated. There is no pain sensitivity.
The pulse in the peripheral arteries is not determined and is felt only in the carotid arteries. Bradycardia and absence of arterial pressure are noted.
Breathing is characterized by rare, short and deep convulsive breathing movements. Swallowing of portions of air is observed. As a result of weakening of the respiratory muscles and accumulation of mucus in the bronchi, breathing becomes hoarse. Sharp pallor of the skin and cyanosis in the limbs are noted.
In addition, a decrease in body temperature and involuntary release of urine and feces are observed.
The duration of the agonal state varies from several minutes to 6 hours. In the absence of first aid, the above stages of the body's dying pass into one another and end in clinical death.
Clinical death is a reversible stage of dying, a transitional period between life and death.
Consciousness is absent, pupils are dilated. Breathing, blood circulation and pulse are not determined. Sharp pallor and coldness of the skin are noted.
Despite the above signs, metabolic processes continue in the body. The duration of clinical death is 3-7 minutes. During this period, it is still possible to restore vital functions with the help of resuscitation measures. At a later stage, the death of cerebral cortex cells occurs, and clinical death turns into biological death.
Subsequently, measures to revive the situation no longer yield results.
The main factors influencing the duration of clinical death include the duration of dying, age and resuscitation methods.
In chronic arterial hypotension (low blood pressure), the prolongation of the preagony and agonal periods makes resuscitation virtually impossible. In cases of rapid dying (acute blood loss, electrical injury, drowning), the duration of clinical death is prolonged, since severe irreversible changes do not have time to develop in the organs and tissues.
In elderly people with chronic diseases, the duration of clinical death is shorter than in young, healthy people. The duration of clinical death is also determined by the methods of resuscitation. Use of an artificial blood circulation apparatus allows you to revive the body even after 20 minutes of clinical death.
6.3. Determining signs of life in a person without consciousness. Sequence of measures to revive the body
Determination of any sign of life is an important condition for carrying out first aid measures.
Signs of life in the absence of consciousness include:
1. Presence of a pulse. In the absence of consciousness, the pulse should be determined only on the carotid arteries. The carotid artery is one of the largest in the human body. It is possible to determine the pulse on this artery even at the lowest pressure.
To determine the pulsation of the carotid arteries, you need to place your fingers in the area of the laryngeal cartilage and also move your fingers to the right or left.
2. Presence of a heartbeat. The heartbeat is determined by the absence of a pulse on the carotid artery with a hand or ear on the left half of the chest.
3. Presence of breathing. Breathing is determined by the movement of the chest and anterior abdominal wall. If this is not possible, the presence of breathing is determined by bringing objects that fog up from the breath to the victim's mouth or nose. Such objects include: a mirror, a watch, glasses, a knife blade, a piece of glass, etc.
Breathing can also be determined by the movement of a piece of cotton wool held to the nostrils.
Pupil constriction during the daytime is determined as follows:
In the dark, to determine the reaction of the pupils, it is necessary to illuminate the eye with any light source.
Sequence of measures to revive the body. Resuscitation, or resuscitation, is a set of emergency measures aimed at restoring blood circulation and breathing when they suddenly stop.
There are 3 stages of carrying out measures to revive the body (Fig. 19).
Fig. 19. Measures to revive the body
Maintaining blood circulation by closed (indirect) cardiac massage.
1. The victim must be on a firm, level surface (table, couch, floor). This surface must be used to prevent the victim's body from shifting during indirect cardiac massage. It is also necessary to raise the patient's legs to ensure blood flow to the brain.
2. The location of the hands is two transverse fingers above the end of the xiphoid process of the sternum.
When performing closed cardiac massage, the hands can be placed one on top of the other "crosswise" (Fig. 20) or "locked" (Fig. 21). When using the "crosswise" method, the fingers should be raised. The hands are positioned perpendicular to the sternum and should not be bent at the elbows. The support is provided on the base of the palms.
Fig. 20. The position of the hands "cross- cross" Fig. 21. The position "hands in a lock"
3. Indirect cardiac massage should be performed vigorously, in a push-like manner, due to the weight of the upper half of the body. In this case, blood is pushed out of the heart chambers through the vascular bed. When performing compression, it is unacceptable to shift the palms relative to the sternum. Closed cardiac massage is performed at a frequency of 100–120 per minute and with the sternum shifted 5–6 cm toward the spine.
Compression is performed taking into account the age characteristics of the body. Indirect cardiac massage in children is performed at a frequency of 100 per minute to a depth of up to 5 cm. In addition, compression is performed on infants with two fingers, and on older children - with one palm.
Resuscitation measures can be started with a single precordial blow.
Restoring and maintaining airway patency. At this stage, Safar's triple technique is performed:
1. Throwing the head back.
2. Forward protrusion of the lower jaw.
3. Opening the mouth.
The head is tilted back as follows: one hand is placed under the victim's neck and raised as high as possible. The other hand is placed on the forehead and pressed on the head (Fig. 22).
Fig. 22. Head tilt |
With the above manipulations, not only does the root of the tongue move away from the back wall of the larynx, but also the mouth partially opens. Throwing the head back ensures the restoration of airway patency.
Moving the lower jaw forward and opening the mouth. After throwing the head back, grasp the victim's lower jaw near the auricle with both hands. Then pull the lower lip with the thumbs and move the lower jaw forward. This results in an even greater opening of the mouth (Fig. 23).
If there is a suspicion of a cervical spine injury (car accident, fall from a height, etc.), it is recommended to limit yourself to just pushing out the lower jaw. If this does not ensure free airway patency, then, regardless of the injury, the head is thrown back. When performing the triple Safar maneuver, it is necessary to examine the oral cavity and, having seen a foreign body (fragments of teeth, a fallen out denture), remove it. For this, you can use a bandage, handkerchief, napkin.
Fig. 23. Protrusion of the lower jaw and opening of the mouth
Maintaining breathing by artificial ventilation of the lungs. There are two main methods of artificial respiration: "mouth-to-mouth" and "mouth-to-nose".
When performing artificial ventilation using the mouth-to-mouth method, pinch the victim's nose, take a deep breath, tightly cover the patient's lips with your lips and exhale. The duration of air blowing should be 1 second. Exhalation into the victim's oral cavity should not be too sharp or large. Air blowing should be accompanied by visible movement of the chest. After these measures, it is necessary to free the patient's nose. The interval between breaths should be 4-5 seconds. When blowing air for hygienic purposes, the victim's mouth should be covered with a handkerchief (Fig. 24).
a b
Fig. 24. Artificial respiration using the mouth-to-mouth method: a – inhale; b – exhale
Artificial respiration using the "mouth-to-nose" method is performed in cases where the patient's mouth cannot be opened (during convulsions, when the lower jaw is damaged, etc.). To perform this method of artificial ventilation, the victim's mouth is closed, a deep breath is taken, the patient's nose is tightly covered with the lips and the breath is exhaled into it. As soon as the chest has risen, the victim's nasal cavity is freed and his mouth is slightly opened, allowing free exhalation.
Fig. 26. Performing artificial respiration. (Video 3 min 41 sec) | |
The compression/breathing ratio is 30:2, regardless of the number of people performing resuscitation. When performing resuscitation, it is necessary to assess the patient's breathing and pulse every 2 minutes (Fig. 26).
Resuscitation is more effective when performed by two rescuers.
Resuscitation activities involving two people are carried out almost continuously and are characterized by uniform distribution of physical load. When providing resuscitation care, rescuers must be changed frequently and quickly.
One of the rescuers constantly holds the victim's head in a tilted position, performs artificial ventilation of the lungs, determines the pulse on the carotid arteries, and counts chest compressions out loud.
Signs of the effectiveness of measures to revive the body include:
The criteria for terminating resuscitation measures are:
Control questions